1. Field of the Invention
The present invention relates to an image forming apparatus capable of handling a digital watermark.
2. Description of the Related Art
In order to detect an unauthorized copy or falsified data, the digital watermarking technology has been employed as a technology for embedding information at the time of printing. The information representing a name of an author, charge information, the allowable number of copying operations or the like, can be mainly cited as information to be embedded as the digital watermark.
Japanese Patent Laid-Open No. 2003-143391 sets forth a process for printing the digital watermark, and specifically describes a technology for printing the digital watermark divided into the background pattern and the front pattern.
Generally, the processing for embedding the digital watermark is implemented in a case where print data from the printer driver is printed onto a recording material. Further, it is also implemented in a case where a document image is copied onto a recording material. That is, image data from a document is read out and printed onto a recording material. In this connection, in a case where it is realized to apply a print processing to a document from which image data is read out, a new use case where the digital watermark is printed onto the document which is read out is to be considered. In such a new use case, for example, in a case where a new digital watermark that updates the contents of a digital watermark printed on the document which is read out is printed on the read document, the contents of updated digital watermark, sometimes, does not match with the intended contents.